Chapter 13

Botkin and KellerEnvironmental Science 5e

Chapter 13

Forests, Parks and Landscapes


The Landscape Concept

• Landscaper Perspective– The concept that effective management and

conservation recognizes that ecosystems, populations and species are interconnected across large geographic areas


Modern Conflicts over Forest Land and Forest Resources

• Silviculture: the the professional growing of trees

• Forests benefit people through public service functions: functions performed by ecosystems for the betterment of life and human existence

• Ex) cleansing of air by trees



The Life of a Tree

• How a Tree Grows– Photosynthesis, Transportation Systems,

Evapotranspiration• Tree Niches

– Determined by • Water content in the soil• Forest tolerance of shade

– There is no single best set of conditions for a forest




A Forester’s View of a ForestOld-Growth Forest: a forest that has never been cutSecond-Growth Forest: has been cut and re-grown

Foresters group trees into:- Dominants, Codominants, Intermediate and Suppressed

Sites are classified by site quality: the maximum timber crop the site can produce in a given time


Clear-Cutting• The cutting of all trees in a stand at the

same time4 types:1. Shelterwood-Cutting2. Seed-Tree Cutting3. Selective Cutting (thinning)4. Strip-Cutting



Plantation Forestry

• Plantation: a stand of single species planted in straight rows

• Properly managed plantations can relieve pressure on forests


Sustainable Forest• Def: Efforts to manage a forest so that a resource in

it can be harvested at a rate that does not decrease the ability of the forest ecosystem to continue to provide that same rate of harvest indefinitely.

• Three are few examples of this. The “certification of sustainable forestry” developed. This involves:– Determining which methods appear most consistent with

sustainability– Comparing the management of a specific forest with

those standards


4 Ways Vegetation Can Effect the Atmosphere:

1. Changing color of the surface and the amount of sunlight reflected and absorbed

2. Increasing the amount of water transpired and evaporated from the surface to the atmosphere

3. Changing the rate at which greenhouse gases are released from the Earth’s surface into the atmosphere

4. Changing the “surface roughness,” which affects wind speed at the surface



Deforestation

• History• Causes • World Firewood Shortage• Indirect Deforestation





Parks, Nature and Wilderness

• Wilderness: an area undisturbed by people

• Managing parks for biological conservation is a relatively new idea. Parks that are too small or in the wrong shape may not be able to sustain their species


Chapter 13

Documents

forest land

specific forest

forest resourcessilviculture

forest ecosystem

forestoldgrowth forest

cutsecondgrowth forest

earths surface

surface roughness